Figure 4.

Comparison of the stimulus alone and heading matched combined stimulus conditions indicate the irrelevant stimulus can interfere with the response. Average spike density histograms for this neuron shows modest responses to the object alone condition (A, right) that increases when the optic flow is added for both the matched (B, right) and the nonmatched (C, right) heading conditions during driving by object motion. This suggests a selective additivity of the 2 alone responses for the object driving combined stimulus conditions. There is no comparable response additivity when driving by optic flow (A–C, left).